Index: lib/CodeGen/MIRParser/MILexer.h
===================================================================
--- lib/CodeGen/MIRParser/MILexer.h
+++ lib/CodeGen/MIRParser/MILexer.h
@@ -113,6 +113,8 @@
     kw_successors,
     kw_floatpred,
     kw_intpred,
+    kw_true,
+    kw_false,
 
     // Named metadata keywords
     md_tbaa,
Index: lib/CodeGen/MIRParser/MILexer.cpp
===================================================================
--- lib/CodeGen/MIRParser/MILexer.cpp
+++ lib/CodeGen/MIRParser/MILexer.cpp
@@ -245,6 +245,8 @@
       .Case("successors", MIToken::kw_successors)
       .Case("floatpred", MIToken::kw_floatpred)
       .Case("intpred", MIToken::kw_intpred)
+      .Case("true", MIToken::kw_true)
+      .Case("false", MIToken::kw_false)
       .Default(MIToken::Identifier);
 }
 
Index: lib/CodeGen/MIRParser/MIParser.cpp
===================================================================
--- lib/CodeGen/MIRParser/MIParser.cpp
+++ lib/CodeGen/MIRParser/MIParser.cpp
@@ -1373,11 +1373,26 @@
 
   auto Loc = Token.location();
   lex();
-  if (Token.isNot(MIToken::IntegerLiteral))
-    return error("expected an integer literal");
   const Constant *C = nullptr;
-  if (parseIRConstant(Loc, C))
-    return true;
+
+  const Module *M = MF.getFunction().getParent();
+  switch (Token.kind()) {
+  case MIToken::kw_true:
+    C = ConstantInt::getTrue(M->getContext());
+    lex();
+    break;
+  case MIToken::kw_false:
+    C = ConstantInt::getFalse(M->getContext());
+    lex();
+    break;
+  case MIToken::IntegerLiteral:
+    if (parseIRConstant(Loc, C))
+      return true;
+    break;
+  default:
+    return error("expected an integer literal");
+  }
+
   Dest = MachineOperand::CreateCImm(cast<ConstantInt>(C));
   return false;
 }
@@ -1884,29 +1899,40 @@
   if (expectAndConsume(MIToken::lparen))
     return error("expected syntax intpred(whatever) or floatpred(whatever");
 
-  if (Token.isNot(MIToken::Identifier))
-    return error("whatever");
-
   CmpInst::Predicate Pred;
+  if (Token.is(MIToken::kw_true)) {
+    if (IsFloat)
+      Pred = CmpInst::FCMP_TRUE;
+    else
+      return error("invalid integer predicate");
+  } else if (Token.is(MIToken::kw_false)) {
+    if (IsFloat)
+      Pred = CmpInst::FCMP_FALSE;
+    else
+      return error("invalid integer predicate");
+  } else if (Token.isNot(MIToken::Identifier)) {
+    return error("expected a predicate");
+  }
+
   if (IsFloat) {
-    Pred = StringSwitch<CmpInst::Predicate>(Token.stringValue())
-               .Case("false", CmpInst::FCMP_FALSE)
-               .Case("oeq", CmpInst::FCMP_OEQ)
-               .Case("ogt", CmpInst::FCMP_OGT)
-               .Case("oge", CmpInst::FCMP_OGE)
-               .Case("olt", CmpInst::FCMP_OLT)
-               .Case("ole", CmpInst::FCMP_OLE)
-               .Case("one", CmpInst::FCMP_ONE)
-               .Case("ord", CmpInst::FCMP_ORD)
-               .Case("uno", CmpInst::FCMP_UNO)
-               .Case("ueq", CmpInst::FCMP_UEQ)
-               .Case("ugt", CmpInst::FCMP_UGT)
-               .Case("uge", CmpInst::FCMP_UGE)
-               .Case("ult", CmpInst::FCMP_ULT)
-               .Case("ule", CmpInst::FCMP_ULE)
-               .Case("une", CmpInst::FCMP_UNE)
-               .Case("true", CmpInst::FCMP_TRUE)
-               .Default(CmpInst::BAD_FCMP_PREDICATE);
+    if (Pred != CmpInst::FCMP_TRUE && Pred != CmpInst::FCMP_FALSE) {
+      Pred = StringSwitch<CmpInst::Predicate>(Token.stringValue())
+                 .Case("oeq", CmpInst::FCMP_OEQ)
+                 .Case("ogt", CmpInst::FCMP_OGT)
+                 .Case("oge", CmpInst::FCMP_OGE)
+                 .Case("olt", CmpInst::FCMP_OLT)
+                 .Case("ole", CmpInst::FCMP_OLE)
+                 .Case("one", CmpInst::FCMP_ONE)
+                 .Case("ord", CmpInst::FCMP_ORD)
+                 .Case("uno", CmpInst::FCMP_UNO)
+                 .Case("ueq", CmpInst::FCMP_UEQ)
+                 .Case("ugt", CmpInst::FCMP_UGT)
+                 .Case("uge", CmpInst::FCMP_UGE)
+                 .Case("ult", CmpInst::FCMP_ULT)
+                 .Case("ule", CmpInst::FCMP_ULE)
+                 .Case("une", CmpInst::FCMP_UNE)
+                 .Default(CmpInst::BAD_FCMP_PREDICATE);
+    }
     if (!CmpInst::isFPPredicate(Pred))
       return error("invalid floating-point predicate");
   } else {
Index: test/CodeGen/MIR/AArch64/parse-integer-true-false.mir
===================================================================
--- /dev/null
+++ test/CodeGen/MIR/AArch64/parse-integer-true-false.mir
@@ -0,0 +1,11 @@
+# RUN: llc -mtriple=aarch64-- -run-pass none -o - %s | FileCheck %s
+# Parse an i1 being a 'true' or 'false'
+---
+name: i1_true_false
+body: |
+  bb.0:
+    ; CHECK: %0:_(s1) = G_CONSTANT i1 true
+    ; CHECK: %1:_(s1) = G_CONSTANT i1 false
+    %0:_(s1) = G_CONSTANT i1 true
+    %1:_(s1) = G_CONSTANT i1 false
+...